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Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!rocksvax!dave
From: dave@rocksvax.UUCP (Dave Sewhuk)
Newsgroups: net.auto
Subject: Re: Detectors Triggering Other Detectors
Message-ID: <366@rocksvax.UUCP>
Date: Sun, 26-Aug-84 15:34:48 EDT
Article-I.D.: rocksvax.366
Posted: Sun Aug 26 15:34:48 1984
Date-Received: Mon, 27-Aug-84 00:41:12 EDT
References: <2988@watcgl.UUCP> <364@rocksvax.UUCP>
Organization: Xerox
Lines: 21

The STOP circuit cannot discriminate between the CW radar signal and
the CW door opener because the signals at the antenna look the
same.  

The way I understand the STOP circuit is as follows, the radiating
radar detectors are scanning the two bands much like the Escort does, but
the local oscillator in the polluting units leaks out the receiver
antenna setting off those radar detectors without a STOP circuit.  
So the signal appears as a rapidly drifting signal in the X and K bands.

When the Escort hears RF coming in it looks to see if there has been a RF
hit in the other band detector within the last few milliseconds.  If so
then it assumes that something just swept through its passband and ignores
the signal.  If you have ever used an Escort without STOP you usually
hear those polluting detectors as signals that beep and bop through
both bands.
-- 
Dave

arpa: Sewhuk.HENR@Xerox.ARPA
uucp: {allegra,rochester,amd,sunybcs}!rocksvax!dave